Overweight and obesity among children and teens in the U.S. has tripled since 1980. Studies have shown that being overweight in childhood and adolescence increases the risk of being overweight and obese in adulthood. If obesity prevalence rates continue on the same trajectory, economic costs are estimated to be between $806 and $957 billion by the year 2030, accounting for 16-18% of total health care costs in the United States. Increasing overweight/obesity rates have been the result of many factors, including unhealthy eating behaviors. The marketing and advertising of energy dense, low nutrition foods and beverages have been found to influence children's eating behavior and preferences. While work has focused on the influence of food and beverage advertising on television, little research has examined the influence of exposure to advertising around schools. Because youth are exposed to advertising around schools on a daily basis, it is crucial to determine how this form of advertising may influence preferences and choices for unhealthy (i.e., energy-dense, low nutrition) foods and beverages. The overarching goal for this study is to develop and validate a spatial, GIS- based measurement tool and protocol that will document and describe outdoor food and beverage advertising around schools. While this measurement tool will be created using data collected around schools, it could be used to document outdoor food and beverage advertising in other venues, as well such as after-school programs, homes, neighborhoods, churches, and parks. Data collected with this tool can then be used by school personnel, local, state, and national policy makers, as well as community and advocacy groups. In addition, the measurement tool and protocol can be used by researchers and practitioners who are interested in analyzing the outdoor food and beverage advertising environment. The specific aim of this study is to: 1) develop and validate a measurement tool and coding protocol to document and describe outdoor food and beverage advertising around 30 middle schools. PUBLIC HEALTH RELEVANCE: The development and validation of a tool to assess food and beverage advertising would be a significant contribution to the growing field of environmental assessment for obesity and other nutrition-related outcomes. Additionally, we will be able to more clearly understand the influence of food and beverage advertising on youth as well as create tools to assist in developing media literacy among youth to impact the growing prevalence of obesity among youth.